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2005 Prius trouble codes.

Discussion in 'Newbie Forum' started by ROGER SMART, Mar 3, 2022.

  1. ROGER SMART

    ROGER SMART New Member

    Joined:
    Mar 3, 2022
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    Location:
    CALIFORNIA
    Vehicle:
    2005 Prius
    Model:
    II
    I have a 2005 Prius. It's throwing trouble codes c1241, c1242, and uo293. It's given us about 50,000 miles of mostly trouble free use (we bought it used). It's also eaten two hybrid batteries (ouch). The uo293 code would seem to indicate control modules and/or the CAN network are screwed. Given the high mileage, and the PITA it would be to troubleshoot the problem I'm thinking it may be time to move on to another vehicle. I hate to do that because I love the Prius. But it may be time. I'm looking for (helpful) input from more knowledgeable Prius owners. I will also be talking with my mechanic (A Prius owner himself.) Thanks in advance folks.
    Roger Smart
     
    #1 ROGER SMART, Mar 3, 2022
  2. ChapmanF

    ChapmanF Senior Member

    Joined:
    Mar 30, 2008
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    Location:
    Indiana, USA
    Vehicle:
    2010 Prius
    Model:
    IV
    Perhaps reassuringly, the words "are screwed" appear nowhere in the Repair Manual documentation of U0293. The code means that some ECU in the car is having trouble communicating with the HV ECU.

    Those communication codes are a bit special, in that you kind of want to know not just what the code is (which tells you which ECU somebody can't communicate with), but also which ECU reported the code (which tells you who can't communicate with it). The ECUs that like to communicate with the HV ECU, and therefore can report U0293, are the battery ECU, the ECM (engine's ECU), and the skid control (braking) ECU.

    Your C1241 and C1242 are both codes that pertain to electrical supply power reaching the skid ECU.

    They do not always mean a problem with the 12 volt battery charge (they could mean problems anywhere on the wiring paths bringing the power to the ECU). But seeing those codes can be a good excuse to double-check the health of the 12 volt battery before fretting too much over worse scenarios. If you manage to correct a low-power problem, you might see the communication code go away also. Worth a try.

    If not, there are step-by-step troubleshooting instructions for those codes in the repair manual (more info).

    When you are searching for information about trouble codes online, it can help to remember that there is never a letter O in a trouble code. If you spell the code right with a zero, as in U0293, you tend to get more and better search results.
     
    #2 ChapmanF, Mar 4, 2022
  3. ROGER SMART

    ROGER SMART New Member

    Joined:
    Mar 3, 2022
    2
    0
    0
    Location:
    CALIFORNIA
    Vehicle:
    2005 Prius
    Model:
    II
    Thanks ChapmanF. I got not only a chuckle, but useful info. Much appreciated. I'm going to call my mechanic today and I'm sure he'll want to do his own trouble shooting of the codes before making a recommendation. In the meantime it is reassuring that the words "are screwed" do not appear anywhere the Prius manual. : )
    Roger
     
    #3 ROGER SMART, Mar 4, 2022
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